Combined hydraulic speed-change, cooling and lubricating system in rotary engine

ABSTRACT

A multipurpose hydraulic system in a rotary IC engine with a hydraulic speed-change mechanism coupled thereto is provide with a common oil pump driven by the engine to pump common oil to the speed-change mechanism to operate the same, to the rotor of the engine to cool the same, and to the engine bearings to lubricate and cool the same.

United States Patent 1 Fujikawa et al.

[111 3,832,980 [451 Sept. 3, 1974 COMBINED HYDRAULIC SPEED-CHANGE, COOLING AND LUBRICATING SYSTEM IN ROTARY ENGINE [75] Inventors: Tetsuzo Fujikawa; Masahisa Kawano; Masaru Yamamoto, all of Akashi, Japan [73] Assignee: Kawasaki Jyukogyo Kabushiki Kaisha, Hyogo-ken, Japan [22] Filed: May 24, 1973 [21] Appl. No.: 363,739

[30] Foreign Application Priority Data May 27, 1972 Japan 47-52870 52 us. Cl. 123/s.01 [51] Int. Cl. F02b 53/14 [58] Field of Search 123/801, 8.05, 41.31,

[56] References Cited UNITED STATES PATENTS 7 3,131,679 5/1964 Peras 123/8.01 3,289,651 12/1966 Jinno l23/8.01 3,301,230 1/1967 Ryusuke 123/8.01 3,743,452 7/1973 Steinwart..... 123/801 3,771,903 11/1973 King 123/801 Primary Examiner-Clarence R. Gordon Attorney, Agent, or FirmEric H. Waters [57] i ABSTRACT A multipurpose hydraulic system in a rotary 1C engine with a hydraulic speed-change mechanism coupled thereto is provide with a common oil pump driven by the engine to pump common oil to the speed-change mechanism to operate the same, to the rotor of theengine to cool the same, and to the engine bearings to lubricate and cool the same.

3 Claims, 2 Drawing Figures PATENTEDSEP :I 3332980 SHEET 2 0F 2 /HYDRAULIC sPEEo- I CHANGE MECHANISM I ,/ENGINE I SIDE 2 I I-IousING I 29 I V I? 34 2 4 -MAIN 2 5 I PAssAGE PASSAGE BEARING MAIN SHAFT CASE I N BEARING BOSS A RoToR 7 I. P I 0 BEARING U 5 DISCHARGE DISCHARGE I 30 PASSAGE I ROTOR PORT PoRT MAIN BEARING I6 I {I3 9 IO H PUMP I I RoToR I 39 on. PUMP ARY IMPELLER RELIEF GEAR GEAR I RELIEF I I VALVE 22 VALVE 255 I TURBINE I SUCTION v ANNULAR f BLAoEs' A PORT G oovE I} r I V I I I PAssAGE PAssAGE 27 PAssAGE I I 1 9 I I CASE on. v 3\ SIDE JACKET I HOUSING I I} I V OIL COOLER COOLING AND LUBRICATING SYSTEM IN ROTARY ENGINE BACKGROUND OF THE INVENTION This invention relates generally to internal combustion engines of the rotary type andto fluid or hydraulic power transmissions and hydraulic speed changing devices. More particularly, the invention relates to a combined hydraulic speed-change, cooling, 'and lubricating system in a rotary internal combustion engine.

In general, an internal combustion engine of rotary type has the remarkable features of smallness and light weight and accordingly is advantageous in that when it is employed as a power source of a power unit, the power unit as a whole can be made compact. In the conventional power unit having in combination a rotary engine and a hydraulic power transmission, or a hydraulic speed-change mechanism, however, the rotor cooling oil and operating oil of the power transmission are supplied by separate oil pumps. This negates the advantage of high compactness of the power unit since additional space for mounting the oil pumps is required, and pump driving mechanisms and piping become complicated. This power unit is also disadvantageous in that since it requires two separate oil pumps, its production cost is accordingly increased.

In a rotary engine of the type which cools its rotor with oil, on the other hand, the cooling oil is continually subjected to a centrifugal force during the cooling operation and tends to flow toward the combustion chambers, thereby not being easily contaminated. Accordingly, it is found that the rotor cooling oil can also be effectively used as operating oil for the hydraulic power transmission. The present invention is based on this discovery and thereby overcomes the abovementioned conventional drawbacks.

SUMMARY OF THE INVENTION According to this invention, briefly summarized, there is provided in a rotary engine of the type referred to above, a multipurpose hydraulic system provided with a common oil pump driven by the engine to pump common oil to the speed-change mechanism for controlled operation thereof, to the rotor of the engine to cool the same, and to the engine hearings to lubricate and cool the same.

The nature, principle, and utility of the invention will be more clearly apparent from the following detailed description with respect to a preferred embodiment of the invention when read in conjunction with the accompanying drawing briefly described below.

BRIEF DESCRIPTION OF THE DRAWING DETAILED DESCRIPTION I In the example shown in FIG. 1, a rotary engine of the type in which an oil-cooled and multi-lobed rotor 8 undergoes a planetary rotational movement within a casing (or center housing) 1 having a .multi-arcuated inner surface is employed as a power source. The hydraulic speed-change mechanism is provided with pump blades 16 and turbine blades 18 and has a constructiona] arrangement in which cooling oil for the rotor 8 and oil for the hydraulic speed-change mechanism are supplied by a common oil pump 13.

The center housing 1 of the rotary engine has cooling fins la thereon and is secured to an output-side side housing 2 with cooling fins 2a and to a magnet-side side housing 3 with cooling fins 3a, thus defining a rotor chamber 4 therebetween. Within this rotor chamber 4, the rotor 8 is fitted onto an eccentric portion 6 of an eccentric shaft 5 by way of a rotor bearing 7, and a rotor gear 9 is adapted to rotate while in meshed engagement with a stationary gear 10. On the output side, the oil pump 13 provided with an external gear 11 connected directly to the shaft 5 and with an internal gear 12 rotating in meshed engagement with the outer gear 11 is accommodated within a pump case 14.

The hydraulic speed-change mechanism is accommodated within a transmission case 19 and includes the pump blades 16 rigidly coupled to the eccentric shaft 5 through a shaft coupling 15 to rotate with a ratio of l I and the turbine blades 18 made integrally with an output shaft 17.

When the engine is started and accordingly the eccentric shaft 5 is rotated, the oil pump 13 operates to pump oil up from an oil jacket 20, which is disposed at a lower portion of the center housing 1, and this oil passes through anoil passage 21 provided in the side housing 2 and enters the pump case 14 through a suction port 22.

After being discharged from a discharge port 23, the oil flows into the rotor 8 by way of an oil passage 24 formed in the side housing 2, and by way of a hole formed in a boss 25 for receiving the output-side main shaft and flows in the arrow direction, as indicated in FIG. 1, cooling the various parts therearound. This oil further flows between the gears 9 and 10 and into an annular groove 26 formed in the side housing 3. After being temporarily stored in the annular groove 26, the oil returns along an oil passage 27 through an oil cooler 28 of conventional type into the oil jacket 20. The lubn'cation of main bearings 29, 30 and the rotor bearing 7 is accomplished by passing a portion of the cooling oil through radial and axial passage holes 31 formed in the eccentric shaft 5.

The foregoing description is directed to the engine side oil supply. Since, on the other hand, the oil pump has a sufficient capacity, a portion of the oil is also introduced automatically into a discharge port 32 disposed on the speed-change'mechanism side. In this discharge port32, a metering orifice 33 is provided for passing therethrough a metered or regulated flowrate of oil. After leaving the discharge port 32, the oil flows I by way of another oil passage 34 formed in the side housing and by way of an oil passage 35 in the case 19 of the speed-change mechanism into the interior 36 thereof.

, The oil thus introduced into the speed-change mech anism is blown against the turbine blades 18 by'the rotation of the pump blades 16 which are rigidly mounted on the eccentric shaft 5. Thus, the oil operates to transmit torque to rotate the output shaft 17 which is integral with the turbine blades 18.

After having finished the torque transmitting operation, the oil passes through another oil passage 37 formed in the transmission case 19 and is merged with another portion of the oil which has cooled the engine side. Then, the merged oil returns into the oil jacket 20 by way of the oil cooler 28.

In the case when in some part of the oil passages described above clogging occurs, and consequently the oil pressures in the discharge ports 23 and 32 rise, a relief valve 38, which may be of a conventional type disposed as indicated in FIG. 2 operates to prevent increase of the oil pressures. As an alternative, another relief valve 39 may be disposed as indicated in FIG. 2 so as to separately control only the oil passages of the speed-change mechanism side.

According to the present invention, oil supply passages both to the engine side and to the speed-change mechanism side are remarkably simplified by the use of the common oil pump 13. As a result, the space to be occupied by the parts and components of the hydraulic system is reduced to make maximum utilization of the high compactness of the rotary engine as a power source in a compact power unit as a whole. Since this feature can be put into practice without providing any special apparatus or means, reduction of production cost, easy maintenance, and other advantageous features are afforded.

It should be understood, of course, that the foregoing disclosure relates to only a preferred embodiment of the invention and that it is intended to cover all changes and modifications of the example herein chosen for the purposes of the disclosurewhich do not constitute departures from the spirit and scope of the invention. For instance, while the example of this invention described above and illustrated in FIG. 1 relates to the specific case of an air-cooled rotary engine, the invention is not so limited, it being applicable with the same effectiveness also to water-cooled engines.

Furthermore, it is possible to use, instead of the gear pump of the directly coupled type illustrated in FIG. 1, a gear pump driven by a belt or a chain or a trochoid pump.

We claim:

1. In a power unit comprising a rotary internal combustion engine of the type having a rotor cooled by oil and a hydraulic speed-change mechanism coupled to the engine and operated with oil, the improvement wherein a common oil pump for supplying said oil for cooling the rotor and said oil for operating the hydrau' lic speed-change mechanism is provided and driven by the engine.

2. In a power unit comprising a rotary internal combustion engine having a rotor cooled by oil and bearings lubricated by lubricating oil and a hydraulic speedchange mechanism coupled to the engine and operated with oil, a combined hydraulic speed-change, cooling, and lubricating system comprising oil reserving means for collecting and holding oil, a common oil pump for supplying oil from said oil reserving means as said oil for cooling the rotor, as said oil for operating the hydraulic speed-change mechanism, and as said oil for lubricating the bearings, and conduit means for conducting the oil through a circulatory path comprising a suction path from the oil reserving means to the oil pump, delivery paths from the oil pump to the rotor, to the hydraulic speed-change mechanism, and to the bearings,

and a return path therefrom back to the oil reserving means.

3. A combined hydraulic speed-change, cooling, and lubricating system as claimed in claim 2 in which there are further provided cooling means for cooling the oil in the return path and dissipating the heat thus extracted to the outside and pressure relief means for preventing rise of oil pressure to abnormally high values in the system. 

1. In a power unit comprising a rotary internal combustion engine of the type having a rotor cooled by oil and a hydraulic speed-change mechanism coupled to the engine and operated with oil, the improvement wherein a common oil pump for supplying said oil for cooling the rotor and said oil for operating the hydraulic speed-change mechanism is provided and driven by the engine.
 2. In a power unit comprising a rotary internal combustion engine having a rotor cooled by oil and bearings lubricated by lubricating oil and a hydraulic speed-change mechanism coupled to the engine and operated with oil, a combined hydraulic speed-change, cooling, and lubricating system comprising oil reserving means for collecting and holding oil, a common oil pump for supplying oil from said oil reserving means as said oil for cooling the rotor, as said oil for operating the hydraulic speed-change mechanism, and as said oil for lubricating the bearings, and conduit means for conducting the oil through a circulatory path comprising a suction path from the oil reserving means to the oil pump, delivery paths from the oil pump to the rotor, to the hydraulic speed-change mechanism, and to the bearings, and a return path therefrom back to the oil reserving means.
 3. A combined hydraulic speed-change, cooling, and lubricating system as claimed in claim 2 in which there are further provided cooling means for cooling the oil in the return path and dissipating the heat thus extracted to the outside and pressure relief means for preventing rise of oil pressure to abnormally high values in the system. 